This invention relates to electrical fuses, and, more particularly, to a fuse/support assembly that permits the convenient utilization of electrical fuses in instrumentation applications.
In many applications, the components of an electrical system are protected against damage from excessive electrical currents by an electrical fuse. The electrical fuse is connected with the electrical system such that any excessive electrical current causes the electrical fuse to change from a closed to an open circuit, preventing the excessive electrical current from passing through and damaging the remainder of the electrical circuit elements. In a typical case, the electrical fuse is connected in series with the components being protected, and includes a fuse link made of a material which heats and melts when the excessive electrical current is applied, thereby breaking the electrical circuit.
The mounting and support of the electrical fuse, and its connection into the electrical system being protected, must be accomplished in a suitable manner. In some electrical systems, such as found in some spacecraft and aircraft, the electrical fuse is externally connected between an electronic unit and an electrical bus. The existing approach to supporting and connecting the electrical fuse utilizes terminal boards to which the electrical fuse is wired, and hand-wired pigtails that extend to the electrical bus and to the electronic unit. This approach requires numerous parts which can be lost as foreign objects into the interior of the structure, and also involves extensive pre-wiring and wire attachments. Rework and repair are difficult for the same reasons.
Accordingly, there is a need for an improved approach to the mounting and interconnecting of an electrical fuse into an electrical system. The present invention fulfills this need, and further provides related advantages.
The present invention provides a fuse/support assembly and a method for its use, for systems wherein an electronic unit is connected to an electrical bus through the electrical fuse. The fuse/support assembly requires no pre-wiring of the electrical bus and reduces the number of terminations at the point of installation. The number of components required to accomplish the fusing is reduced as compared with prior approaches. Installation, rework, repair, and inspection are all simplified as compared with prior approaches, and there is reduced likelihood of loss of parts and resulting foreign object damage of the system. The close contact of the fuse/support assembly to the electrical bus allows the electrical bus to serve as a heat sink and stabilize the fuse/support assembly to prevent a premature activation of the fuse.
In accordance with the invention, a fuse/support assembly for attachment to an electrical bus comprises a base plate, comprising a substrate made of an insulator and having a contact location thereon, and an electrically conductive path on the substrate, with the electrically conductive path extending between the contact-location and a second location. A fastener structure brings the contact location of the electrically conductive path into contact with the electrical bus. There is an external connector structure. A fuse is supported on the substrate, with a first side in electrical communication with the external connector and a second side in electrical communication with the second location of the electrically conductive path.
This approach simplifies the electrical fuse protection of electrical systems, where the fuse is mounted exterior to the components being protected. Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. The scope of the invention is not, however, limited to this preferred embodiment.